Steve Jobs, the co-founder and CEO of Apple Inc, has died aged 56. Here are some key dates from his life and work:

1972: Jobs enrolls at Reed College in Portland, Oregon, but drops out after a semester.

1974: Jobs works for video game maker Atari and attends meetings of the Homebrew Computer Club with Steve Wozniak, a high school friend who was a few years older.

1975: Jobs and Wozniak attend Homebrew Computer Club meetings.

1976: Apple Computer is formed on April Fool's Day, shortly after Wozniak and Jobs create a new computer circuit board in a Silicon Valley garage. A third co-founder, Ron Wayne, leaves the company after less than two weeks. The Apple I computer goes on sale by the summer for $666.66.

1993: Apple introduces the Newton, a hand-held, pen-based computer. The company reports quarterly loss of $188 million in July. Sculley is replaced as CEO by Apple president Michael Spindler. Apple restructures, and Sculley resigns as chairman. At Next, Jobs decides to focus on software instead of whole computers.

1994: Apple introduces Power Macintosh computers based on the PowerPC chip it developed with IBM and Motorola. Apple decides to license its operating software and allow other companies to "clone" the Mac, adopting the model championed by Microsoft Corp.

1995: The first Mac clones go on sale. Microsoft releases Windows 95, which is easier to use than previous versions and is more like the Mac system. Apple struggles with competition, parts shortages and mistakes predicting customer demand. Pixar's "Toy Story," the first commercial computer-animated feature, hits theaters. Pixar goes to Wall Street with an IPO that raises $140 million.

1996: Apple announces plans to buy Next for $430 million for the operating system Jobs' team developed. Jobs is appointed an adviser to Apple. Gil Amelio replaces Spindler as CEO.

1997: Jobs becomes "interim" CEO after Amelio is pushed out. He foreshadows the marketing hook for a new product line by calling himself "iCEO." Jobs puts an end to Mac clones.

1998: Apple returns to profitability. It shakes up personal computer industry in 1998 with the candy-colored, all-in-one iMac desktop, the original models shaped like a futuristic TV. Apple discontinues the Newton.

2000: Apple removes "interim" label from Jobs' CEO title.

2001: The first iPod goes on sale, as do computers with OS X, the modern Mac operating system based on Next software. Apple also releases iTunes software.

2003: Apple launches the iTunes Music Store with 200,000 songs at 99 cents each, giving people a convenient way to buy music legally online. It sells 1 million songs in the first week.

2004: Jobs undergoes surgery for a rare but curable form of pancreatic cancer. Apple discloses his illness after the fact.

2005: Apple expands the iPod line with the tiny Nano and an iPod that can play video. The company also announces that future Macs will use Intel chips.

2006: Disney buys Pixar for $7.4 billion. Jobs becomes Disney's largest individual shareholder, and much of his wealth is derived from this sale.

2007: Apple releases its first smartphone, the iPhone. Crowds camp overnight at stores to be one of the first to own the new device.

2008: Speculation mounts that Jobs is ill, given weight loss. In September he kicks off an Apple event and says, "The reports of my death are greatly exaggerated," making a play off a famous Mark Twain quote after Bloomberg News accidentally publishes, then retracts, an obituary that it had prepared in advance.

2009: Jobs explains severe weight loss by saying he has a treatable hormone imbalance and that he will continue to run Apple. Days later he backtracks and announces he will be on medical leave. He returns to work in June. Later it is learned that he received a liver transplant.

2010: Apple sells 15 million of its newest gadget, the iPad, in nine months, giving rise to a new category of modern touch-screen tablet computers.

Jan. 17, 2011: In a memo to Apple employees, Jobs announces a second medical leave with no set duration. Cook again steps in to run day-to-day operations. Jobs retains CEO title and remains involved in major decisions.